<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style type="text/css">
*{
border: 1px solid red;
}
</style>
</head>
<body>
  <div onclick="alert('div')">
    <p onclick="alert('p')">
      <input type="button" value="按钮" onclick="alert('按钮')">
    </p>
  </div>
</body>
</html>